1. Technical Field
The present disclosure relates to a light-emitting device, and in particular to a light-emitting device comprising a plurality of recesses in a semiconductor window layer.
2. Description of the Related Art
The light-emitting diodes (LEDs) of the solid-state lighting elements have the characteristics of the low power consumption, low heat generation, long operational life, shockproof, small volume, quick response and good opto-electrical property like light emission with a stable wavelength, so the LEDs have been widely used in household appliances, indicator light of instruments, and opto-electrical products, etc. However, how to improve the light-emitting efficiency of light-emitting devices is still an important issue in this art.